| 摘要 |
<p>Lightweight aggregate is produced by pelletizing fly ash, preheating the pellets for between 8 and 15 minutes at a temperature between 1200 DEG and 1800 DEG F., and finally sintering, e.g. at a temperature between 1900 DEG and 2800 DEG F. Prior to the preheating step the pellets may be subjected to preliminary heating at 300-1000 DEG F. for 4-8 minutes. The products are stated to have a much lower stain index than conventional fly ash aggregates.</p> |
